s=input()s1=''if s.count(')')==s.count('(') and s.count('[')==s.count(']') and s.count('}')==s.count('{') and s.count('>')==s.count('<'):    for char in s:        if char =='(':            s1+=char        if char ==')':            if len(s1)>0:                if s1[len(s1)-1]=='(':                    s1=s1[:-1]        if char =='[':            s1+=char        if char ==']':            if len(s1)>0:                if s1[len(s1)-1]=='[':                    s1=s1[:-1]        if char =='{':            s1+=char        if char =='}':            if len(s1)>0:                if s1[len(s1)-1]=='{':                    s1=s1[:-1]        if char =='<':            s1+=char        if char =='>':            if len(s1)>0:                if s1[len(s1)-1]=='<':                   s1=s1[:-1]    if len(s1)==0:        print('true')    if len(s1)!=0:        print('false')else:    print('false')